lxc: ensure setns() syscall is defined
lxc: ensure setns() syscall is defined

Older versions of glibc don't provide the setns() syscall
function wrapper, so we must define it ourselves to prevent
build failure on old distros.

Signed-off-by: Daniel P. Berrange <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

taget/libvirt,taget/libvirt,taget/libvirt,rlaager/libvirt,VenkatDatta/libvirt,zippy2/libvirt,andreabolognani/libvirt,agx/libvirt,nertpinx/libvirt,taget/libvirt,libvirt/libvirt,VenkatDatta/libvirt,crobinso/libvirt,libvirt/libvirt,jfehlig/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,andreabolognani/libvirt,zippy2/libvirt,libvirt/libvirt,olafhering/libvirt,taget/libvirt,olafhering/libvirt,datto/libvirt,eskultety/libvirt,zippy2/libvirt,nertpinx/libvirt,eskultety/libvirt,datto/libvirt,olafhering/libvirt,rlaager/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,nertpinx/libvirt,nertpinx/libvirt,jardasgit/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,jfehlig/libvirt,andreabolognani/libvirt,agx/libvirt,agx/libvirt,jardasgit/libvirt,crobinso/libvirt,libvirt/libvirt,rlaager/libvirt,rlaager/libvirt,crobinso/libvirt,agx/libvirt,jardasgit/libvirt,eskultety/libvirt,VenkatDatta/libvirt,datto/libvirt,jfehlig/libvirt,eskultety/libvirt,datto/libvirt,VenkatDatta/libvirt,zippy2/libvirt,crobinso/libvirt,rlaager/libvirt,agx/libvirt,fabianfreyer/libvirt,olafhering/libvirt,nertpinx/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,eskultety/libvirt,datto/libvirt,fabianfreyer/libvirt